Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating revenues:
Investment management fees	$ 3,138.5	$ 2,720.9	$ 2,120.2
Service and distribution fees	780.3	645.5	412.6
Performance fees	37.9	26.1	30.0
Other	135.5	95.2	64.5
Total operating revenues	4,092.2	3,487.7	2,627.3
Operating expenses:
Employee compensation	1,246.2	1,114.9	950.8
Third-party distribution, service and advisory	1,282.5	1,053.8	737.0
Marketing	86.0	78.5	65.3
Property, office and technology	254.6	238.4	212.3
General and administrative	295.4	262.2	166.8
Transaction and integration	29.4	150.0	10.8
Total operating expenses	3,194.1	2,897.8	2,143.0
Operating income/(loss)	898.1	589.9	484.3
Other income/(expense):
Equity in earnings of unconsolidated affiliates	30.5	40.2	27.0
Interest and dividend income	11.0	10.4	9.8
Interest income of consolidated investment products	307.2	240.9	0
(Gains)/losses of consolidated investment products, net	(138.9)	114.0	(106.9)
Interest expense	(61.8)	(58.6)	(64.5)
Interest expense of consolidated investment products	(187.0)	(118.6)	0
Other gains and losses, net	49.0	15.6	7.8
Income before income taxes	908.1	833.8	357.5
Income tax provision	(286.1)	(197.0)	(148.2)
Net income	622.0	636.8	209.3
(Gains)/losses attributable to noncontrolling interests in consolidated entities, net	107.7	(171.1)	113.2
Net income attributable to common shareholders	$ 729.7	$ 465.7	$ 322.5
Earnings per share:
- basic	$ 1.58	$ 1.01	$ 0.77
- diluted	$ 1.57	$ 1.01	$ 0.76
Dividends declared per share	$ 0.4775	$ 0.4325	$ 0.4075